Beta-ureidoisobutyrate (betaUIB) is increased in the urine of patients with beta-ureidopropionase (EC 3.5.1.6) deficiency (PMID: 12271438 ), a gentic disorder. Ureidoisobutyric acid can be used to predict patient's individual phenotypes of enzyme deficiencies in pyrimidine metabolism when associated with a risk for severe toxicity against the antineoplastic agent 5-fluorouracil (PMID: 12798197 ).

Enzymes

Catalyzes the second step of the reductive pyrimidine degradation, the reversible hydrolytic ring opening of dihydropyrimidines. Can catalyze the ring opening of 5,6-dihydrouracil to N-carbamyl-alanine and of 5,6-dihydrothymine to N-carbamyl-amino isobutyrate.